i have a 1989 7.5 onan dkd gen with i think a D950 engine with 400hr, has been setting for 3 years when it starts engine rpm go up to around 4000 or more rpms for about 2 sec and then falls down to 1800 rpm and runs normal ,, anyone have any ideas
D950 over revs on startup
- Thread starter BOATMAN11
- Start date
Sounds like the governor in the injection pump is sticking. Don't let it over rev like that until you get it fixed.
North Idaho Wolfman
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Pull the injectors out and have them pop tested, sounds like you have one that's leaking.
That will cause the engine to over fuel and over rev till it burns off the extra fuel.
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From my understanding of reading the manuals and seeing a good puff of smoke just after start, the engine starts at full or close to full throttle then immediately governs to the 1860 rpm. My tractor starts the same way. I would suggest an additive with solvents to un-stick the pump slide. I have heard that Seafoam is good. Try adding some 2 cycle outboard oil to the fuel. Start and stop it several times.
A good spray lube will help w/ any build up on the outside{old oil build up} & some good additive for the insides..{injector cleaner or sea foam}
Your throttle is locked to 1800, yes.?? if u have a "manual" throttle on it.. u could lowwer the rpm w/ the adjustment screw.. & only throw it to full at start up & quickly bring it down w/ the manual throttle..below 1800 & bring it back up to your liking when its warmed up..
IF u have access to the control rack.. keep spraying it & working the throttle.{by hand}
IF that doesnt help, the sticking is internal & has to be handled as such.. {fuel additive}
Your throttle is locked to 1800, yes.?? if u have a "manual" throttle on it.. u could lowwer the rpm w/ the adjustment screw.. & only throw it to full at start up & quickly bring it down w/ the manual throttle..below 1800 & bring it back up to your liking when its warmed up..
IF u have access to the control rack.. keep spraying it & working the throttle.{by hand}
IF that doesnt help, the sticking is internal & has to be handled as such.. {fuel additive}
Most late style generators have a lot of electronics in them and the Voltage regulator can be harmed if the engine RPM is run too low. My suggestion would be to disconnect the generator voltage regulator FIRST.
I want to recommend a website where we have a GREAT Onan page. Lots of old Onan techs. These guys will really be able to help.
Your DKD is a very sought after and stout generator. I have about 10 old Onans from 1958 to 1993. All are capable sets. https://www.smokstak.com
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